that are endowed with very great agility. Nothing is more curious than
to see the particle of camphor successively ascend and descend the
strongly pronounced curves presented by the mercury near the sides of
the vessel that contains it. On raising the temperature of the metal
slightly, the motions of the camphor on its surface are accelerated, and
the same effects occur with water that has been slightly heated.

The experiments that we have just called attention to show what
importance slight impurities may have upon certain results. "They
prove," says our learned colleague Mr. Daquin, "that there exists upon
polished substances an imperceptible coating of those fatty matters
which serve to-day to explain Moser's images." We find therein also a
manifest proof and a rational explanation of those grave errors into
which the presence of these fatty matters, that have hitherto been
scarcely suspected, led so clever and so distinguished a scientist as
the illustrious discoverer of endosmosis.--_N. Joly, in La Nature_.

* * * * *




CARBONIC ACID IN BEER.


We present a diagram, on exposition at the last Brewers' Convention in
Detroit, of the racking device, devised by J. E. Siebel in 1872, and
used at that time in the brewery of Messrs. Bartholomae & Roesing, in
Chicago. The object of the apparatus is to retain as much carbonic acid
in the beer as possible while racking the same off into smaller packages